How useful is a 2v/4v measure for an AVR preout ?

[waynel]

Amir usually shows a plot with SINAD with output voltages swept. It's not a case of AVRs being optimized for one voltage vs another. For the amps tested that have good SINAD at 1.4V but poor SINAD at 2V, this is the result of a DESIGN FLAW , not an "optimization". I'm growing tired of your circular arguments on this topic and am left with one or two possible conclusions:
1) You genuinely don't understand the issue ( If this is the case, I've tried to explain)
2) You are trolling

For my sake , I hope it's the first case and for your's I hope it's the second and you knock it off.

 

[Gedeon]

As far as I know all these analog designs must run away from noise in the low end and from distortion in high end.

Engineers with limited budget (almost everyone in the planet) must choose where to put that optimal operation range.

 

[waynel]

As far as I know all these analog designs must run away from noise in the low end and from distortion in high end.

Engineers with limited budget (almost everyone in the planet) must choose where to put that optimal operation range.

I'm an engineer. This is a nonsense argument. The problem is a design flaw not an optimization.

 

[Thomas savage]

This is getting nowhere and it's becoming bad tempered.

Can we all move on Please.

 

[John Galt]

Can we drop this topic for now?

I'm sure a few more AVRs will be reviewed in due time and then we can examine the measured data again.

FWIW, I’ve found it informative.

 

[peng]

The premise of this thread is basically that having a good SINAD at 1.2v-1.5v and a mediocre one at 2v will give cleaner sound in most setups than having a good SINAD at 2.0v and a mediocre one at 1.2v - 1.5v. That's what I defend (always talking about RCA unbalanced)

That is logically correct if 1.2-1.5 V satisfies your needs with sufficient headroom. In reality SINAD performance of the preamp/vol chip varies with output level not in a straight line and/or single slope form and may perform better at above 1.5 V anyway. It is quite often a little V shaped. Below are the graphs of the chip used in the Denon and Marantz, the one used in Yamaha and Onkyo models are very similar.

So there is no evidence that we need to be concerned about 2 V being an issue, except in some odd cases, such as the Marantz AV7705 that did not perform all that great at 1.2 V (actually 2.4 V unbalanced), but even then, -75 dB is nothing to be concerned with for most HT application, I would think..

https://www.njr.com/electronic_device/products/NJU72343.html

It also seems often enough that ASR measurements showed best performance happened at above 1.2-1.5 V, below is a recent example:

 

[waynel]

https://www.njr.com/electronic_device/products/NJU72343.html

View attachment 70520

This chip is not the primary problem, It would allow for ~-106dB distortion at 1khz at 2V output.